The present invention relates to an ink-jet print method and apparatus for performing a print operation by discharging an ink from an ink-jet head onto a recording member, a color filter, a display device, and an apparatus having the display device.
With recent advances in personal computers, especially portable personal computers, the demand tends to arise for liquid crystal displays, especially color liquid crystal displays. However, in order to further popularize the use of liquid crystal displays, a reduction in cost must be achieved. Especially, it is required to reduce the cost of a color filter which occupies a large proportion of the total cost. Various methods have been tried to satisfy the required characteristics of color filters while meeting the above requirements. However, any method capable of satisfying all the requirements has not been established. The respective methods will be described below.
The first method is a pigment dispersion method. In this method, a pigment-dispersed photosensitive resin layer is formed on a substrate and patterned into a single-color pattern. This process is repeated three times to obtain R, G, and B color filter layers.
The second method is a dyeing method. In the dyeing method, a water-soluble polymer material as a dyeable material is applied onto a glass substrate, and the coating is patterned into a desired shape by a photolithographic process. The obtained pattern is dipped in a dye bath to obtain a colored pattern. This process is repeated three times to form R, G, and B color filter layers.
The third method is an electrodeposition method. In this method, a transparent electrode is patterned on a substrate, and the resultant structure is dipped in an electrodeposition coating fluid containing a pigment, a resin, an electrolyte, and the like to be colored in the first color by electrodeposition. This process is repeated three times to form R, G, and B color filter layers. Finally, these layers are calcined.
The fourth method is a print method. In this method, a pigment is dispersed in a thermosetting resin, a print operation is performed three times to form R, G, and B coatings separately, and the resins are thermoset, thereby forming colored layers. In either of the above methods, a protective layer is generally formed on the colored layers.
The point common to these methods is that the same process must be repeated three times to obtain layers colored in three colors, i.e., R, G, and B. This causes an increase in cost. In addition, as the number of processes increases, the yield decreases. In the electrodeposition method, limitations are imposed on pattern shapes which can be formed. For this reason, with the existing techniques, it is difficult to apply this method to TFTs. In the print method, a pattern with a fine pitch is difficult to form because of poor resolution and poor evenness.
In order to eliminate these drawbacks, methods of manufacturing color filters by an ink-jet system are disclosed in Japanese Patent Laid-Open Nos. 59-75205, 63-235901, and 1-217320. In these methods, inks containing coloring agents of three colors, i.e., R (red), G (green), and B (blue), are sprayed on a transparent substrate by an ink-jet system, and the respective inks are dried to form colored image portions. In such an ink-jet system, R, G, and B pixels can be formed at once, allowing great simplification of the manufacturing process and a great reduction in cost.
When a color filter is to be manufactured by such an ink-jet system, an ink may be discharged onto each pixel to color each pixel portion while an ink-jet head having a plurality of ink discharging nozzles is scanned over a color filter substrate. In this case, however, since the amounts of ink discharged from a plurality of ink discharging nozzles slightly vary, if one pixel array is colored by one nozzle, adjacent pixel arrays are colored by nozzles whose ink discharging amounts differ from each other. It is known, therefore, that color irregularity occurs between the pixel arrays. To reduce such color irregularity, a method of performing a scanning operation a plurality of times, and coloring pixel arrays by using different nozzles in the respective scanning operations has been proposed. In this method of coloring each pixel array by performing a scanning operation a plurality of times, however, inks discharged in the respective scanning operations may overlap at some portions in each pixel array, resulting in an insufficient effect of reducing the color irregularity, unless the manner of distributing inks in the respective scanning operations is studied.
The present invention has therefore been made in consideration of the above problems, and has as its object to provide an ink-jet print method and apparatus which can uniformly distribute inks within each line when the each line is to be printed in a plurality of scanning operations.
It is another object of the present invention to provide a color filter manufactured by the above print method and apparatus, a display device using the color filter, and an apparatus having the display device.
In order to solve the above problems and achieve the above objects, an ink-jet print method according to the present invention is characterized by the following process.
There is provided an ink-jet print method for printing lines on a recording member, in which each line is printed on a recording member by a plurality of scanning operations of an ink-jet head having a plurality of ink discharging nozzles while changing the ink discharging nozzle used to print the each line for every scanning operation, comprising discharging the inks discharged in the plurality of scanning operations such that the inks are arranged at equal intervals within the each line.
An ink-jet print apparatus according to the present invention is characterized by the following arrangement.
There is provided an ink-jet print apparatus for printing lines on a recording member, in which each line is printed on a recording member by a plurality of scanning operations of an ink-jet head having a plurality of ink discharging nozzles while changing the ink discharging nozzle used to print the each line for every scanning operation, comprising scanning means for scanning the ink-jet head relative to the recording member, and control means for controlling an operation of the scanning means and an ink discharging timing of the ink-jet head such that the inks discharged in the plurality of scanning operations are arranged at equal intervals within the each line.
A color filter according to the present invention is characterized by the following arrangement.
There is provided a color filter manufactured by coloring each pixel array on a substrate by a plurality of scanning operations of an ink-jet head having a plurality of ink discharging nozzles while changing the ink discharging nozzle used to print the each pixel array for every scanning operation, wherein the color filter is manufactured by discharging the inks discharged in the plurality of scanning operations such that the inks are arranged at equal intervals within the each line.
A display device according to the present invention is characterized by the following arrangement.
There is provided a display device including a color filter manufactured by coloring each pixel array on a substrate by a plurality of scanning operations of an ink-jet head having a plurality of ink discharging nozzles while changing the ink discharging nozzle used to print the each pixel array for every scanning operation, integrally comprising the color filter manufactured by discharging the inks discharged in the plurality of scanning operations such that the inks are arranged at equal intervals within the each line, and light amount changing means for changing a light amount.
An apparatus including a display device according to the present invention is characterized by the following arrangement.
There is provided an apparatus including a display device including a color filter manufactured by coloring each pixel array on a substrate by a plurality of scanning operations of an ink-jet head having a plurality of ink discharging nozzles while changing the ink discharging nozzle used to print the each pixel array for every scanning operation, comprising the display device integrally including the color filter manufactured by discharging the inks discharged in the plurality of scanning operations such that the inks are arranged at equal intervals within the each line and light amount changing means for changing a light amount, and image signal supply means for supplying an image signal to the display device.
Other objects and advantages besides those discussed above shall be apparent to those skilled in the art from the description of a preferred embodiment of the invention which follows. In the description, reference is made to accompanying drawings, which form a part hereof, and which illustrate an example of the invention. Such example, however, is not exhaustive of the various embodiments of the invention, and therefore reference is made to the claims which follow the description for determining the scope of the invention.